As is well-known in the art, electric motors have stator assemblies including a plurality of teeth and stator coil windings wound around each of the teeth so electrical current flowing through the windings can generate magnetic fields to drive rotation of a rotor. It is often desirable to increase the number of times the windings are wrapped around each tooth, but there is only a limited amount of space for windings in the slots between the teeth. Also, some of the equipment used to wind the windings around the teeth has to move through the slots between adjacent stator teeth. As the windings fill up the slots during the winding process, it becomes more difficult to wind the coils on the teeth, particularly at the high speeds required for economical mass production of electric motors.
Because of the limitations of winding equipment, slot fill (the percentage of the volume of the slots between stator teeth that is occupied by stator windings) for full round stator constructions is limited to about 65 percent. Segmented stators have been developed to address this problem. Segmented stators are made of multiple discrete segments, each of which includes one or more teeth. The windings are wrapped around the stator teeth while the segments are separate from one another. In the case of single-tooth segments, the winding equipment is not constrained by any other teeth during the winding process. In the case of multi-tooth segments, the separation of the segments during winding still provides better access to the slots and enables a higher slot fill to be achieved. However, the various stator segments have to be assembled after winding. Moreover, the windings around each tooth of the stator are connected to the windings around other stator teeth and there is a need to provide structure to hold the different segments of a stator in proper position relative to one another during winding. These factors add to the cost and difficulty in manufacturing a motor or other electromagnetic machine using a segmented stator.